This article addresses the benefits of audio-visual input for learning second language (L2) vocabulary and grammatical constructions. Specifically, it explores the role of frequency, the effects of subtitles and captions, and the mediating role of learner proficiency on language gains in two longitudinal studies. Study 1 targets vocabulary acquisition in two groups of adolescents with an elementary L2 proficiency level who view 24 episodes of a TV series spread weekly over a whole academic year, one group with subtitles (first language) and one with captions (second language). Study 2 targets grammar acquisition in two groups of university students with an intermediate proficiency level who view 10 episodes over five weeks, one group with captions and one without captions. Results of both studies show significant correlations between language gains and frequency in the input, but the size of the frequency effect appears to depend on the type of support provided by the on-screen text. The analyses also show no significant advantage of captions or subtitles for vocabulary learning at this proficiency level, a significant advantage of captions over no captions for grammatical constructions learning, as well as the significant role of proficiency. It is concluded that viewing audio-visual material leads to L2 learning and it can support learners in their preparation for study abroad and maximize their learning experience during their sojourn.

本文介绍了视听输入对于学习第二语言（L2）词汇和语法结构的好处。具体来说，它在两个纵向研究中探讨了频率的作用，字幕和字幕的影响以及学习者熟练程度对语言获得的中介作用。研究1的目标受众是两组具有基本L2水平的青少年，他们在整个学年中每周观看24集电视连续剧，其中一组带有字幕（第一语言），另一组带有字幕（第二语言）。研究2的目标是两组中等水平的大学生的语法习得，他们在五周内观看了10集，一组带有字幕，一组没有字幕。两项研究的结果都表明，输入的语言增益与频率之间存在显着的相关性，但是频率影响的大小似乎取决于屏幕上文字所提供的支持类型。分析还显示，在此熟练程度下，标题或字幕在词汇学习中没有显着优势，与没有标题的语法构造学习相比，标题的显着优势以及熟练程度的显著作用。结论是，观看视听资料可以促进L2学习，并且可以支持学习者为出国留学做准备，并在他们逗留期间最大程度地提高他们的学习经验。分析还显示，在此熟练程度下，标题或字幕在词汇学习中没有显着优势，与没有标题的语法构造学习相比，标题的显着优势以及熟练程度的显著作用。结论是，观看视听资料可以促进L2学习，并且可以支持学习者为出国留学做准备，并在他们逗留期间最大程度地提高他们的学习经验。分析还显示，在此熟练程度下，标题或字幕在词汇学习中没有显着优势，与没有标题的语法构造学习相比，标题的显着优势以及熟练程度的显著作用。结论是，观看视听资料可以促进L2学习，并且可以支持学习者为出国留学做准备，并在他们逗留期间最大程度地提高他们的学习经验。